We propose to develop a novel testing platform for enabling rapid, ultrasensitive, accurate, user-friendly, and cost-effective point-of-care respiratory diagnostics for viral infections. Viral respiratory infections result in hundreds of thousands of deaths and millions of illnesses each year and are especially serious in children, the elderly, and the immunocompromised patients. Rapid and accurate diagnosis of respiratory disease improves treatment, substantially lowers inappropriate antibiotic use, and minimizes costs from unnecessary exploratory testing. Current diagnostic methods for respiratory infections include culture, which takes days; rapid immunoassays, which can be insensitive; direct fluorescent immunoassays, which require technical expertise; and nucleic acid amplification, which is expensive and complex. Many small and medium sized hospitals lack the resources for the most sensitive viral diagnostics and therefore the ability to quickly diagnose patients for respiratory virus infections. We aim to develop a rapid and sensitive test for a panel of respiratory viruses based on our proprietary technology which uses a low-cost non-magnified digital imaging system that counts target molecules tagged with fluorescent particles. The system will require no specialized training and no pre- processing of samples. The Specific Aims of this feasibility study are to (1) demonstrate the technology's ability to rapidly (within 5 minutes) detect viral antigens in respiratory samples about 1000-fold more sensitively than current rapid tests; (2) develop an inexpensive prototype consumable that is as easy to use as an over-the- counter pregnancy test and that demonstrates the feasibility of testing for a panel of respiratory markers; (3) develop a simple low-cost prototype imaging instrument; and (4) using infected respiratory samples, demonstrate improved performance of the new assay compared to commercialized rapid methods by comparing the results of both methods to the results obtained using nucleic acid tests as the gold standard. Achieving these Aims should justify a Phase 2 project that will focus on developing pre-commercial prototypes of the consumable and instrument and increasing the range of the assay to include a panel of the most medically important respiratory viruses and indicators of other types of respiratory illness such as allergies and bacterial infection. The commercial impact of this unique point of care platform ranges beyond the large potential market for the clinical respiratory panel in community hospitals, clinics, and physicians' offices. The platform also has the potential to address other significant unmet needs in clinical medicine, industrial microbiology, and environmental microbiology. PUBLIC HEALTH RELEVANCE: The commercialized point-of-care testing system will have a substantial impact on the diagnosis and treatment of viral respiratory disease, which is a major source of illness in the United States with an estimated 1.5 billion respiratory infections causing hundreds of thousands of deaths every year. The new test will enable, for the first time, ultrasensitive, accurate, and cost-effective diagnosis of respiratory disease in community hospitals, clinics, and physicians' offices. Today, healthcare workers in these venues generally send samples to reference laboratories, precluding the ability to get early results. By delivering on-site results quickly, the test system proposed here has the potential to speed up delivery of the appropriate therapy, eliminate unnecessary and invasive testing, shorten hospital stays, and improve patient outcomes. [unreadable] [unreadable] [unreadable]